In connection with the conveying of loose insulation for receipt by cavities in a wall structure, an apparatus has been previously devised for delivery of the insulation so that it has a fluffy constituency when received by the wall cavity. This apparatus is disclosed in U.S. Pat. No. 4,111,493 to Sperber, issued on September 5, 1978, and entitled "Feeding Apparatus for a Pneumatic Conveying System." With regard to the operation of this apparatus, pressurized air is used in carrying the insulation from the apparatus. Some of the pressurized air does not exit the apparatus carrying the insulation, rather, it travels in a direction towards the incoming insulation leading to unwanted blow back of the insulation, i.e. the pressurized air tends to force the incoming insulation in a direction away from the exit or output area. In accordance with the apparatus disclosed in the aforesaid prior art patent, a vent opening is provided to define a passageway for such air so that blow back is eliminated, or at least reduced. The vent opening is formed in a front wall of a cylindrical rotary pocket feeder. The pocket feeder includes a number of vanes, each having a seal member attached at the ends of the vanes. As the vanes rotate, any pressurized air, that may have not exited with the insulation, is carried until it communicates with the vent opening, at which time the pressurized air is able to exit the rotary pocket feeder for the intended purpose of avoiding blow back. It has been observed, however, that under certain conditions this arrangement does not satisfactorily overcome the blow back problem. Specifically, when the material being delivered to the pocket feeder is relatively light and fluffier and/or the material particles are fed at a relatively low flow rate, blow back air interferes with material particle flow to an unacceptable level. That is, because the particles are lighter and fluffier and/or the particles fall at a slow rate, a relatively small amount or rate of blow back seriously impedes material flow into the pocket feeder. Consequently, the present invention is directed to providing at least one air passageway that results in a more acceptable and efficient escape of blow back air so it does not undesirably affect material particle flow into the pocket feeder.
In connection with this prior art apparatus, it has also been noted that the seal members tend to wear whereby more pressurized air than is desirable is able to escape past the seal members between the vanes. As a result, greater amounts of air are available for contributing to the blow back problem. That is, not all such air escapes via the vent opening but some may flow through the inlet that receives the incoming material Thus, it would also be advantageous to provide a feeding apparatus that circumvents this concern relating to the wear of the seal members.
Relatedly, the apparatus of the '493 patent utilizes a single wall member and a control member to pivotally move the wall member and thereby adjust an inlet opening formed in the chute to the rotary pocket feeder. This construction is not a satisfactory solution to the blow back problem when lighter and fluffier particles are utilized. Consequently, a more accommodating inlet adjusting assembly is necessary in which air can pass or be vented adjacent to the inlet adjusting assembly.